Method of and system for selective energy transmission



Jan, 13; 1925. 1,522,882

J. H. HAMMOND, JR

METHOD OF AND SYSTEM FOR SELECETIVE ENERGY TRANSMISSION Original Filed March 1 1912 mymron a fiITOR MEYS Patented Jan. 13, 1925.

JOHN HAYS HAMMOND, JR., 0]? GLOUCESTER, MASSACHUSETTS.

METHOD AND SYSTEM FOR SELECTIVE ENERGY TRANSMISSION.

Application filed march 16, 1912, Serial No. 684,309. Renewed November 23, 1921. Serial No. 517,878.

To all whom it may concern:

Be it known that I, JOHN Hers HAM- MOND, Jr., a citizen of the U 'ted States, residing at Gloucester, in the S ate of Massachusetts, have invented certain new and useful Improvements, in Methods of and Systems for Selective Energy Transmission, of which the following is a specification.

My invention relates to improvements in methods of and systems for the transmission of energy, and more particularly to a method of and system for utilizing the phenomena of interference of either the wave frequencies or group frequencies of electric waves to produce beats or increased intensity at intervals determined by the relation that the several frequencies bear to, each other.

One' of the objects of the invention is to provide a method of energy transmission which shall be selective and non-interferable. Various other objects of the invention will be more fully set forth in the following description of certain forms of ap-- paratus embodying the invention as applied .to the transmission of energy without wires, although the invention is not limited in its scope to the particular form of apparatus shown. s

In the accompanying drawings:

Figure 1 represents diagrammatically one form of apparatus embodying my invention and adapted to receive ether-waves of different wave frequencies. 7

Figure 2 represents diagrammatically a modified form of apparatus adapted to receive ether-waves having predetermined, different group frequencies.

Referring to the accompanying drawings and. particularly to Figure 1 thereof, the antenna circuit 1 is tuned by means of the self-inductance 2 and condenser 3 to a predetermined periodicity, and the antenna circuit 4 is tuned by means of the self-inductance 5 and the condenser 6 to adifferent, predetermined periodicity.

A closed, oscillatory circuit 7 which comprises a self-inductance 8 and a variable condenserv 9 is inductively coupled to the circuit 1, and a corresponding, closed circuit 10 which comprises a self-inductance 11 and variable'condenser 12 is inductively coupled to the circuit 4. The circuits 7 and 10 are also inductively. coupled to a common beat circuit 14 by means of coupling coils 15, 16 and 17, 18 respectively.

A rectifier19 is inserted in the circuit 14 so as to permit flow of current in one direc-- tion and to prevent flow of current in the other direction. A coupling coil 20 is also inserted in the beat circuit 14. In the use of this arrangement, the current in the coil 20 pulsates at a frequency equal to the beat frequency.

An oscillator circuit 21 is coupled to the beat circuit 14 y the coils 20 and 22 and is tuned to the beat frequency by means of adjustment thereof a apacity 24. Said circuit may also be provided with a suitable current indicator such as, for instance, a telephone receiver 25.

In operation, it maybe assumed that the circuit 7 is tuned to a periodicity of 100,000 oscillations per second and the circuit 10 istuned to a periodicity of 105,000 oscillations per second. Then upon reception of waves of the above-mentioned periodicities, beat currents of a frequency of 5,000 cycles per second are produced in the circuit 14. Consequently, if the circuit 21 is tuned to a frequency of 5,000 cycles per second, it will respond to the beat frequency of the circuit 14.

As is well known in the art, a telephone rceiver will respond to each audio frequency impulse which passes through it. Accordingly, in the use of the arrangement shown in Fig. 1, the indicator 25, since it has the form of a telephone receiver, not only gives an indication of the passage of current through it, but emits a note which varies with the frequency of the actuating impulses. Therefore, if in the use of the arrangement shown very powerful waves are impressed upon the antennae 1 and 4 having frequencies such as to set up beat frequency current of a frequency of, for example, 4,500 cycles per second, instead of a frequency of 5,000 cycles per second, in the oscillatory circuit 21, the operator could readily. distinguish between the desired signals and the interfering waves by the diiference in the note produced by them in the telephone receiver. It must be understood,however, that since the indicator circuit 21, in the case assumed, is uned to a beat frequency current,

'of' 5,000 cycles per second, waves'of frequencies such as to cause a beat frequency of 4,500 cycles per second will not-operate the telephone receiver 25 unless they are of very great strength, so that under normal condi tions the telephone'receiver 25 will not be operated except by signal waves which produce a beat frequency current of 5,000 cycles.

shown'in Fig. 1, certain of the advantages is coupled to the coil 3.

' will respond to of the invention may be attained without the use'of the oscillatory circuit 21 and with the'telephone receiver connected in the circuit 14, since although the omission of the oscillatory circuit 21 involves the loss of the important-advantage of such circuit in selecting only beat frequency currents of the frequency to which the circuit is tuned, nevertheless,i nasmuch as the telephone. receiver emits a note determined by the freuency of the. current passing through it, t e operator can, under ordinary conditions of operation,; discriminate thenote of the desired signals from notes or other sounds produced by interfering currents.

The modified form of construction shown in Figure 2 is adapted to receive transmitted energy having predetermined group frequencies. This form of the 1nvent1on permits the reception of high frequency energy emittedin groups withoutfear of interference by forced oscillations since the receiving means is syntonizedto group frequency, In

this construction the antenna '1 is in circuit with the self-inductances 2 and 3 and the condenser 4. The closed, oscillatory circuit 7 is coupled to the coil 2, and the circuit 10 In this. arrangement, assuming that the circuit is tuned to high frequency waves emitted wlth a group frequency of 400 and the circu t 10 to another high frequency emitted wlth a group. frequency of 600, then beats will be produced in circuit 14 at the rate of 200 per second. Consequently, if the circuit 21 is tuned to a frequency of 200 per second, 1t the beat frequency of the circuit 14. l If the circuit 21 be tuned to a certain beat frequency, this will permit the frequencies transmitted and received to be varied at will so long as the difference between said frequencies remains constant and equal to the frequency to which circuit 21 is tuned.

In the art, it is well known that in order to attain eflicient tuning it is necessary to have circuits whose electrical .osclllationis persistent and slowly dampened; Therefore,

in all cases where I have shown detectors it -may be understood that I may employ such detecting devices as .present the least ohmic resistance 11f a c1rcu1 Although the particular apparatus described is adapted especially to the wireless jtransmission of'energy, it is obvious-that the invention may be advantageously; employed in other modes of energy .trans1nission.

Neither is .the'invention limitedj'to the trans mission signals, since 'thejreceived energy can be utihzed for selective operation of va- 'rious mechanical arrangements and devices, nor is the invention limited to the use of frequencies now-commonly used in the wireless transmission of signals- It will be obvious also that various combinations can be made antenna circuits responsive respectively to high frequency undamped radiant impulses. of different periodicities, in combination with a circuit electrically tuned to the difference between the periodicities of said impulses.

2. A systeni of selective energy transmission having at the recelving station local 00'- antenna circuits responsive to high f'requency impulses of different periodicities, a closed circuit to-which each of said circuits is coupled, and a separate circuit coupled with said closed circuit and electrically 95..

tuned to the difference between the periodicities of said impulses.

3. A system of selective energy transmission comprising a plurality of closed oscillatory circuits tuned to predetermined riodicities, a beat circuit coupled to each of said closed circuits and comprising a rectifier, and an independent circuit coupled to said beat circuit and tuned to the beat frequency of said common circuit and comprising a current detector.

4. A system of selective energy transmission having at the receiving station local circuits responsive respectively to radiant waves of different group frequencies, in combination with a circuit electrically tuned to the specific difference of group frequencies of said waves. I 4 '5. A system for receiving radiant energycomprising two receiving devices tuned to 1 15 respond to radiant impulses of diiferent frequences respectively and a third receiving device arranged to be controlled as a result of the joint action ofsaid first mentioned devices and tuned to, respond toimpulses having a frequency equal to the difference between said first mentioned frequencies.

6. A system for receiving radiant energy comprising two receiving devices arranged to respond selectively to electro radiant'impulses of different frequencies res ectively,

a rectifier and a third receiving evice arranged to be controlled as a result of the joint action of said first mentioned devices and the rectifier and tuned to respond to 9- impulses having a frequency equal to the difference between said firsts'mentioned frequencies. V

7. A system for receiving radiant energy comprising two antenna circuits tuned to respond to radiant impulses of difierent frequencies respectively, a rectifier, a third circuit arranged to be controlled as a result of the joint action of said first mentioned circuits and the rectifier and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies, and a telephone receiver connected with said third circuit.

8. A system for receiving radiant energy comprising two receiving circuit arrangements constructed to selectively absorb from the ether and transmit electro radiant impulses of different frequencies respectively, a rectifier, a third receiving circuit arranged to be controlled .as a result of the joint action of said first mentioned circuit arrangements and the rectifierr and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies, and a telephone receiver in said third circuit.

9. A system for receiving radiantenergy comprising two antenna circuits tuned to respond to radiant impulses of different frequencies respectively and a third receiving circuit arranged to be controlled as a result.

of the joint and simultaneous action of said first mentioned circuits and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies.

10. A system for receiving. radiant energy comprising two antenna circuits tuned to respond to electro radiant impulses of different frequencies respectively, a rectifier, a

.third receiving circuit arranged to be controlled as a result of the joint and simultaneous action of said first mentioned circuits and the rectifier and tuned to respond to impulses having a frequency equal to the differences between said first mentioned frequencies, and a telephone receiver in said third circuit. I

11. A system for receiving radiant energy, comprising two receiving devices constructed to selectively absorb from theether and transmit radiant impulses of different frequencies respectively, both of csaid frequencies being above the frequency of sound waves which gives a maximum audibility for a given amplitude of'said sound waves,

and a third receiving device arranged to be controlled as a result of the joint and simultaneous action of said first mentioned devices and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies.

12. A system for receiving radiant energy, comprising two antenna circuits tuned to respond to radiant impulses of difierent frequencies respectively, both of said frequencies being substantially above audibility, a rectifier, and a third receiving circuit arranged to be controlled as a result of the joint action of said first mentioned circuits and the rectifier and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies.

13. A system for receiving radiant energy, comprising two antenna circuits tuned to respond to radiant impulses of difierent said frefrequencies respectively, both of quencies being above the frequency of sound waves which gives a'maximum audibility for a given amplitude of said sound waves,

a rectifier, a third receiving circuit arranged to be controlled as a result of the joint and simultaneous action of said first mentioned circuits and the rectifier and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies, and a telephone receiver connected with said third circuit.

14:. A system for receiving radiant energy, comprising two antenna circuits tuned to respond to radiant impulses of different frequencies respectively, a cuit coupled to said first mentioned circuits, a rectifier in said third circuit, and a fourth circuit coupled to said third circuit and tuned to impulses having a frequency equal to the difierence between said first mentioned frequencies.

15. A system for receiving radiant energy, comprising two antenna circuits tuned to respond to radiant impulses of different frequencies respectively, each of said frequencies being above the frequency of sound waves which gives a maximum audibility for a given amplitude of said sound waves and said frequencies difiering from each other by an audio frequency, a rectifier, a third receiving circuit coupled to both of said first mentioned circuits through the rectifier and tuned to respond to impulses having a frequency equal to the audio-freuency difierence between said first mentioned frequencies, and a telephone receiver connected with said third circuit.

16. A system for receiving radiant energy, comprising a plurality of antenna circuits tuned to respond to radiant impulses of different frequencies respectively, both of said frequencies being above the frequency of sound waves which gives a maximum audibility for a given amplitude of said sound wav s, a rectifier circuit coupled with said antenna circuits, and a device arranged to be controlled as a resultof the joint action 'of' said circuits and tuned to respond to impulses having a frequency equal to the difference between said first-mentioned frequencies.-

third cirof the current a plurality of specific high 17 A system for receiving radiant energy, comprising a plurality, of antenna circuits tuned to respond to radiant impulses'of different frequencies respectively, both of said frequencies being above the frequency of sound waves which givesa maximum audibility for a given amplitude of said sound waves, and a device arranged .to be controlled as a result of the joint and simultaneous action of said circuits and tuned to respond to impulses having a frequency equal to the difference between said first mentioned frequencies. I

18. A transmitting system arranged for the reception of energy having the form of frequency electrical etheric oscillations of different periodicities, including a receiving station responsive only tothe simultaneous reception of said specific 'etheric oscillations having a circuit for combining and rectifying said oscillations, and a second circuit coupled to said circuit and respon ive only to said rectified combined electrical oscillations.

19. A transmitting syste 1 arranged for the reception of energy hav'ng the form of a plurality'of specific high frequency electrical etheric oscillations of different periodicities, including a. receiving station responsive only to thesimultaneous reception of said specific etheric oscillations having a circuit for combining said oscillations, means in said circuit for rectifying the oscillations, and a, second circuit inductively coupled to said circuit and-responsive'only to said rectified combined electrical oscillain frequency produce 1n said circuit a beat current 'varytions.

20. A system for receiving radiant energy comprising a circuit, means for combining in said circuit two series of high frequency radiant impulses differing from each other by such an amount that they -'ing in amplitude at an audio frequency, said means comprising elements for selectively a bsorbing. each of said series ofiradiant' inipulses from the ether and transmitting it to said circuit, a rectifier in said" circuit for producing direct current impulses'having a frequency corresponding to thezfre uency'of the variations in amjglitude of the eat current, and a telephon receivercon'nected' to' said circuit and actingfto give indications of a character dependent upon the frequency in the circuit;

21. A system for receiving radiant energy comprising a circuit, means for combining in said circuit two series of high frequency radiant impulses differing from each-other in a frequency characterlstic by suchan amount that they produce in said circuit a beat current varying in amplitude at a predetermined fr'equency, said'aneans comprising elements .for selectively absorbing each of said series of-radiant impulses from the ethernndtransmitting it to said circuit, a rectifier in said first-mentiohed circuit for producing direct current impulses having a frequency corresponding to the frequency'of l the variations in amplitude of the beat current, and a telephone receiver connected to said circuit.

22.' A method of signaling which consists energies, producing electrical oscillations as v a result of the actlon of said comblned energiesand indicating the presence of said last named oscillations only when the frequency thereof'equals the difference between the fre quenciesof said segregated series of impulses. 23. A method of signalling which consists in transmitting energv through the-ether in such aform as. to include two series of periodic impulses having different, predeter- 1nined frequencies respectively, selectively receiving the energy of said series of 'impulses, combining and rectifying said received energy to produce oscillations having a frequency equal to the difference between said frequencies, and producing indications by said oscillations of a character dependent upon the frequency of the oscillations causing the indications so that indications produced by said oscillations can be distinuished-from indications produced by oscilations of a different frequency.

24; A method of signalling which consists in transmitting energy through the ether in such a form'as to include two series tively receiving the energy of said series of impulses, combining and rectifying said re- 'ceived energy to'produce oscillations having a freqpency equal to the difference between said from interfering oscillations, and producing indications by said oscillations of a character dependent'upon the frequency'of the oscillations causing the indications so that indications produced by said, oscillations can be distinguished from indications produced by oscillations of a different frequency.

This specification signed and witnessed this 27th day of February, AID. 1912.

OI-IN HAYS HAllIMON'D, JR. I .Witnesses; r 1- ALBERT W. S ows-1,; Many GKmo.

equencies, selecting saidoscillations 

